#define  _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main()
{
	int n = 0;
	scanf("%d", &n);
	char ch[55] = { 0 };
	scanf("%s", ch);
	int i = 0;
	while (ch[i] != '\0')
	{
		if (ch[i] + n > 'z')
			ch[i] -= 26;
		ch[i] += n;
		i++;
	}
	printf("%s", ch);
	return 0;
}
